Method for concentrating titanic oxid from substances containing it and iron oxid.



- as are,

METHOD FQR CONCENTRATING TITANIC OXID FROM SUBSTANCES CONTAINING IT AND IRON OXID.

Specification of Letters Patent. Application filed November 29, 1912. Serial No.

No Drawing.

Patented Aug. 11, 1914. 733,945.

To all whom it may concern:

Be it known that we, AUGUSTE J. Rossr and Louis E. BARTON, both citizens of the United States, and residents of Niagara Falls, in the county of Niagara and State of New York, have jointly invented certaln new and useful Improvements 1n Methods for Concentrating Titanic Oxid fron Substances Containing It and Iron Ox1d, of which the following is a specification.

Uses of titanic oxid in the arts are now extensive and increasing. A long standing problem has been, and still is, its accumulation, on industrial scales of manufacture, in sufiicient quantity and purity, and at the least possible cost.

Numerous known substances contain greater or less percentages of titanic oxid (TiO Natural titanlc oxid 1s, as well known, widely and plentifully existant 1n ores, but, almost invariably, so entangled, or combined, with other oxids, and constituents of the gangue, as to render it, as mined, unavailable for most industrial purposes. As thus found, in varying percentages,.1n enormous BXlSlllll deposits of so-called titanifcrous-iron, or ilmeno-rutile, ores, it is particularly associated with corresponding percentages of iron oxids, from which it has hitherto proved practically impossible, without prohibitory expense, to so complctely separate it as to render it avallable for many desired industrlal uses. Even the purest of such ores, being those commonly called rutile, ores, though of much higher titanic oxid content than any others, as high for example as 95%, contain nevertheless percentages of iron oxids, sllica and earthy bases, such as alumma, rendering them, in natural state, unsatisfactory contnbutors of titanic oxid in the manufacture of certain special products, and, moreover, deposits of such rutile ores have hitherto been discovered only in segregated quantities too small to supply existing industrial demand. Moreover the said ores usually contain more or less ilmenite being a compound of titanic oxid and iron oxid designated by the formulas FeTiO or FeOTiO which compounds we believe to have hitherto proved too refractory for any commercially practicable method of deriving titanic oxid from such last mentioned ores.

thoroughly melt our said mixture 0 reactions,

The objects of our present invention compr se production of methods whereby titanic be more completely separated from the other, and particularly the iron, constituents of said ores, and this more rapidly, simply, and economically, and with a better resultant titanic oxid product than heretofore. We attain these objects by our present improved method as follows :--We first finely pulverize the ore and thoroughly mix the resulting powder with hydroxid of an alkali metal, preferably caustic soda, i. e. sodium hydroxid (N aQH). The proportion of soda thus employed as such should be amply sufficient to enable it to fully react, during our next step, with all constituents of the ore having chemical afinity therefor. Excess of soda above this is neither injurious, pensive for reasons hereinafter stated. For example, in treating an ore which analyzed Titanic oxid 52 Iron oxids 40 Silica no; 3 Alumina. 4

we obtained excellent results by adding the soda in a proportion of 58 parts (of a 70% N e 0 commercial caustic soda) to each 100 parts of ore, as we prefer that the proportion of soda added should be sufficient to insure formation during our next step of sodium titanate (N a TiO but: We do not limit ourselves to such proportion, having attained by our process good results with considerably less soda. Our next etc is to ore and sodium hydroxid. The melting operation is preferably conducted in an electric furnace, but it may of course be accomplished by any other means capable of insuring a thorough and complete melt, as for example in an open hearth urnace heated by a direct coke fire in a grate, or indirectly by producer gas, such furnaces bein of course lined with material sufiiciently re ractory to resist the action of the charge during the melt. During the latter we believe that the following among others, occur in the charge, viz :Oxid of sodium combines with oxid of titanium to form titanate of soda, thus readily breaking up the said ilmenite molecules present and releasing in a state afterward-soluble, as hereinafter described, iron oxid constituents. Ferrous oxid of iron is more or less oxidized to ferric oxid. Silica and alumina of the gangue combine with the oxid of sodium to form silicates and aluminates of soda. The melt is then cooled and well crushed,say to about mesh. It is then repeatedly and-thoroughly lixiviated in heated, preferably boiling, Water, until substantially all of said titanate of soda has been decomposed into titanic oxid and caustic soda. The soda thus set free, also any excess soda, and said silicates and aluminates, ctc., being soluble, dissolve and are thus removed from the remaining melt with the Water of lixiviation. The soda lye resulting from said lixiviation may be evaporated to a cake of soda useful in treating as aforesaid the next charge of ore. In our practice we have thus repeatedly recuperated from to %of the soda employed, the which constitutes a notable economy of our present method. What remains undissolved of the melt duringits aforesaid lixiviation is separated, as by decantation, and may be expected to be substantially free from excess of soda and from silica and alumina and their compounds, but to retain substantially all of the titanic oxid and iron oxids, the which are insoluble in water, and also some slight remainders of gangue including magnesia, the ores referred to containing not to substantially exceed traces of lime. The said remainder of the melt we then treat,preferably While still moist, to a heated, preferably boiling, bath containing acid so dilute as to dissolve therein iron, rather than titanium, compounds, preferably sulfuric acid, owing to the latters comparative cheapness, and superior results, though other suitable acids, such as hydrochloric for example, may be employed. In this step of our method we have, with excellent results, proportioned the water of the bath to be from three to four times the weight of the therein boiled melt, and the acid, for example sulfuric acid, in proportion of from about twenty-nine parts to each twenty parts of said remainder of the melt. Though, by these proportions, the

sulfuric acid is in considerable excess, it is not wasted, since it may be withdrawn, or decanted, to be used, with or without addition of fresh acid, in treatment of the next charge. This last mentioned treatment of the melt we continue for about an hour, after which the titanic acid, the which remains in the bath undissolved, will settle to the bottom, and, being separated, as by decantation,

these settlings Will, if our method has been properly followed as above, be found, after calcining them, to consist of pure titanic oxid in proportion as high as from 94% to 96%. We are thus enabled to produce from ordinary titaniferous-iron, or ilmeno-rutile, ores, and, as We believe, by a more rapid,

simple, and economical process than heretofore, a titanic ox1d product higher 111 its percentage of that compound than the bestand rarest rutile ores, and this at a cost very greatly below the present market prite of such last mentioned ores. Moreover by repeating our said process on our said product it may thereby, the same as may such rutile ores, be readily, and economically, bro-ught/ to contain still higher percentages of pure bauxite, or even rutile or ilmenite previously fused with carbonate of soda, be fluxed with acid sodium sulfate or. sodium pyrosulfate for the express purpose of dissolving out or rendering soluble. the titanic oxid contained in such materials, after which the resulting melt is directed to be treated with dilute sulfuric acid maintained however so acidified as to prevent the titanic oxid from precipitating out of its said solution. We do not of course claim any such procedures, the which in operation and results are obviously the reverse of our own, it being observed that in our aforesaid method the conditions are such that the natural titanic oxid is throughout prevented from dissolving or forming other compounds requiring heretofore necessitated protracted and expensive boiling or other treatment to insure its prccipitation and separation from the bath. lVe believe ourselves to be the first to flux the raw titaniferous material with hydroxid of an alkaline metal, thereby breaking up the ilmenite molecules, and also thereby forming titanates, substantially all of which latter, during our lixiviation in Water, part with their soluble soda, while substantially all of the thus liberated titanic oxid being insoluble, under the conditions of said dilute acid bath, settles immediately therein as such, or more or less hydrated, without dissolving, whereby iron oxids present are sepa rated therefrom because, under said conditions, reacting to form sulfates which remain in solution in said bath. \Ve are also aware that it has been asserted, prior to our invention, that titanic acid may be obtained from suitable bauxite containing a percentage thereof besides alumina, silica and ferric oxid, by stirring the same into sulfuric acid of degrees Tw., the solution beingafterward diluted to 60 degrees Tw., and boiled until the dissolved titanic acid precipitates, but this again is not our process for the reasons aforesaid, it being borne in mind thatthe latter avoids substantially entirely such previous productions of acid, soluble, compounds of titanic acid as preliminary steps, that our process is aimed at, in no believe, been heretofore possible, at least I when operating on industrial scales, he,

sides whichwe' obtain more directly a'more natural, purer, and we believe therefore, for

many purposes, more efficient titanic oxid product. I v

It will be notedthat caustic potash, (2'. e. potassium hydroxid, KOH),jcan be used in the same way, and with like efiect, ascaustic soda, in the practice of our invention; in

fact the hydroxid of any alkaline metal may, if desired, be so substituted for sodium hydroxid. It will however be appreciated that the latter is economically, and therefore industrially, more desirable so long as present comparative market prices of these respective oxids are maintained, and moreover We also prefer the latter because. of its superior action and effect in the practice of our said method.

It will be understood that carbonate of soda might, though with inferior results and at greater expense, be used as a substitute for a hydroxid of an alkali metal in the practice of our method, and this without departing from our invention, the which, in its broadest aspects, comprises the step of melting the substance containing titanic and iron oxids with oxid of an alkali metal in novel combination with our aforesaid steps of lixivlatlng 1n water the resulting melt and subjecting the remainder thereof to the action of a bath containing an acid so dilute as to dissolve therein iron, but not therein titanium, compounds, as hereinbefore described. But our researches have demonstrated that no other compounds of sodium, or alkaline compounds of soda, are capable of producing, with equal rapidity, elfectiveness and completeness, the reactions required to separate the titanic from the other oxid therewith entangled as are said hydroxids of alkali metals, including particularly caustic soda, when, as per our method, charged as such in making our melt. The employment, in this connection, of even carbonate of soda we have found comparatively ineflicient, inasmuch as, while this may ultimately result in production in the melt of soda to a greater or less extent, it requires, owing to its necessarily greater relative bulk, to its content of carbonic anhydrid, and to its greater stability, additional. treatments, or at least expenditure of additional time and heat, to insure even its inferior performance of said required reactions, as evidenced for example by the instance hereinbefo-re referred to in which, owing to the aforesaid substantially prohibitory characteristics of said carbonate, the product derived from its fusion with the titanic an;

solved residue K i 4,015., 5, rutilt 81 ilm'enitgis' stb eqaaila in acid. sodiufn sulfate, etc.,- i'noi' 'e'r to render it s a.-

t 1 While, we have, prticularly referred, throughout our prce, ing 'spec1fication, to oi'es we do not wis thereby to confine the app ication of opr methods t'o ores ,specifi:

it, being understood that such application to any other suitable substance,' or material, containing titanic acid andiron oxid is also feasible and within the purview of our invention and claims. What we claim as new and desire to secure by Letters Patent is the following, v1z: v

' 1; The method of obtaining titanic oxid (TiO from a substance containing it and iron oxid, which comprises melting said substance together with oxid of an alkali metal, l-ixiviating the resulting melt in hot water, withdrawing the undissolved residue of said melt and subjecting it to the action of a bath containing acid so dilute as to dissolve therein iron, rather than titanium, compounds.

2. The method of obtaining titanic oxid (TiO from a substance containing it and iron oxid, which comprises melting said substance together with hydroxid of an alkali metal charged as such, lixiviating the resulting melt in hot water, withdrawin the undissolved residue of said melt and subjecting it to the action. of a bath containing sulfuric acid so dilute as to dissolve therein iron, rather than titanium, compounds.

3. The method of obtaining titanic oxid (TiO from a substance containing it and iron oxid, which comprises melting said substance together with sodium hydroxid charged as such, lixiviating the resulting melt in hot water, Withdrawing the undissolved residue of said melt and subjecting it to the action of a bath containing acid so dilute as to dissolve therein iron, rather than titanium, compounds.- I

4. The method of obtaining titanic oxid (TiO from a substance containing it and iron oxid, which comprises melting said substance together with sodium hydroxid charged as such,,1ixiviating the resulting melt in hot water, withdrawing the undisof said melt and subjecting it to the action of a bath containing sulfuric acid so dilute as to dissolve therein iron, rather than titanium, compounds. 7

5. The method of obtaining titanic oxid (TiO. from a substance containing it and iron oxid, which comprises melting said substance together with oxid of an alkali metal, lixiviating the resulting melt in hot water, withdrawing the undissolved residue of said melt, subjecting it to the action of a bath containing acid so, dilute as to dissolve therein iron, rather than titanium, comiiiied with: I

pounds, and finally withdrawing and calcinin the undissolved residue.

(5. [he method of obtaining titanic oxid ('liO from a substance containing it and iron oxid, which com. rises melting said substance together wit hydroxid of an alkali metal charged as such, lixiviating the resulting melt in hot water, withdrawing the undissolved residue ofsaid melt and subjecting it to the action of a bath containing sulfuric acid so dilute as to dissolve therein iron, rather than titanium, compounds, and finally withdrawing and calcining the undissolved residue.

' 7. The method of obtaining titanic oxid (Ti0 from a substance containing it and iron oxid, which comprises melting said substance together with sodium hydroxid charged as such, lixiviating the resulting melt in hot water, withdrawln the undissolved residue of said melt an subjecting it to the action of a bath containin acid'so dilute as to dissolve therein iron, rafiier than titanium, compounds, and finally withdrawing and calcium the undissolved residue.

8. The metho of obtaining titanic oxid (TiO from asubstance containingit and iron oxid, which com rises meltin said substance together wit sodium hy roxid charged as such, lixiviating the resulting melt in hot water, withdrawing the undissolved residue of said melt and subjecting it to the action of a bath containing sulfuric acid so dilute as to dissolve therein iron, rather than titanium, compounds, and finally withdrawing and calcining the undissolved residue.

AUGUSTE J. ROS'SI. 4 LOUIS E. BARTON. Witnesses:

WALTER D. EDMoNns, PHILIP O. PECK. 

